Process for treating textiles



Patented Oct. 21, 1941 UNITED STATES PATENT OFFICE rnooass ron mama TEXTILES Roger Wallacli, Briarclii! Manor, N. Y.,as|ignor to Sylvania Industrial Corporation, Fredericksburg, Ya... a corporation of Virginia No Drawing. Application September-24, 1938, Serial No. 231,521. InGreat Britain October (01. sias) 3 Claims.

This invention relates to the treatment of a textile material and, more particularly, it is concerned with a process for the treatment of textiles, and includes correlated improvements and discoveries designed to enhance the character of ing the fabric in a flimsy and cheap-looking condition. Moreover, such temporarily sized textiles lose a substantial quantity of the mineral filler upon mere heating or rubbing.

Accordingly, it is a serious disadvantage of prior starched goods that they are, before laundering too still and after laundering too soft, i. e.

that there is such a marked difference in the handle before and after washing. It is believed that this diiference is largely due to the fact that the textiles have been treated with starch which was in solution, thereby forming on the goods a stiff substantially continuous film. I The starched film imparted to the goods a stiff paperlike handle before laundering, but the film being largely broken up and washed out during laundering, the final product was relatively soft. It has also been proposed to back-fill a textile with a cellulose ether compound containing a large quantity of a filler, but such composition is not sufilcie'ntly anchored to the textfle, if it is applied directly to the dry fabric.

It has been found that to increase the useful life of textiles, it is necessary that the treating composition be firmly anchored to the textileand efi'ect a permanent binding of the filler.

It is a general object of the present invention to improve the appearance, feel and durability of textiles by treating such goods witha composition containing a filler which is permanently bound and anchored to the texti It is a specific object of the invention to improve the handle and appearance of textile by finishing them with a composition which does not show a marked difference in stiffness in the treated goods before or after washing.

It is a further object of the invention to pro-' vide a method for increasing the durability and permanence of a starch size on textiles.

Other objects of theinvention will in part be obvious and will in part appear hereinafter.

- dyeing, softening, or other The process of the invention comprises, in general, impregnating a textile with a composition containing a coagulable film-forming substance which does not contain a substantial quantity of filler and with or without coagulating the filmforming substance but before completely drying the composition, thereafter applying to the im- 7 pregnated textile while it is in a moist condition a composition containing a coagulable film-forming substance and a substantial quantity of a filler and treating the textile to insolubilize the film-forming substances of both compositions. The finishing process of the invention may be 'used for impregnating throughout or back-filling textiles. For back-filling textiles by the now preferred embodiment, a textile is back-filled with a composition containing a coagulable filmforming substance which does not contain a substantial quantity of a filler, gelling the composition by partial coagulation or partially drying the composition and thereafter again backfilling the textile by applying over the first applied composition, while that composition is in a moist gel condition, a second composition containing a coagulable film-forming binder con-.

taining a substantial quantity of a filler and then treating the textile to insolubilize the film-forming substance of both compositions.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others thereof, which will be exemplified in the process hereinafter disclosed, and the scope of the invention will be indicated in the claims.

The process is applicable for treating textiles of various kinds, more particularly those formed in whole'or in part of cellulosic fibres, for exampie, cotton, flax, ramie, rayon and the like, or combinations thereof. The process may be carried out on the textile before or after bleaching,

treatment.

The film-forming substance employed in the impregnating composition and/or in the backfilling composition may comprise a suitable nonfibrous cellulosic film-forming substance such as regenerated cellulose; cellulose derivatives, for example, cellulose ethers, cellulose hydroxyethers, cellulose ether-esters; cellulose esters, such as, cellulose formate, cellulose nitrate, cellulose acetate; cellulose xantho-fatty acids and their esters; cellulose isothiocy\a nates; cellulose thiourethanes; hydroxy-alkyl cellulose xanthates, and the like; and synthetic and natural film-forming resins, for example, polymerized urea resins, and the like. The regenerated cellulose may be derived from viscose; cuprammonium cellulose solutions, and from solutions of cellulose in solvents such as zinc" chloride, metal perchlorates, tetra-aikyl ammonium hydroxide, amines and the like. Further, it may be formed in situ on the cellulose esters such as nitrocellulose.

The filler may be a suitable inert water-insoluble, solid substancef It may consist of an inorganic compound or the corresponding natural' occurring mineral, desirably purified, for example, talc (soapstone), clay (kaolin), barium sulphate (permanent white), zinc oxide (Chinese white), titanium dioxide (anatase), and the like, and mixtures thereof, and/or an organic filler, such as starch, comminuted vegetable fibres, as wood flour, comminuted non-fibrous cellulosic material, such as finely ground cellulose hydrate, cellulose esters, cellulose ethers, and the like.

In a preferred embodiment of the invention, the filler comprises starch or starch-like material such, for example, as potato starch, wheat flour, maize starch (corn starch), tapioca flour and modified starches, such as dextrln and the like, or prepared powdered vegetable substance made from locust bean, such as St. J ohns bread.-

Toka gum is a trade name under which such powdered vegetable substances are commonly merchandised. It is to be understood, however, that when starch and starch-like materials are used as 'flllers in this invention they are added to the second applied coating composition as undissolved particles or granules and the starch or starch-like material is not dissolved or disintegrated in solution before being added to the film-forming substance although the starch granules may be highly swollen. In other words, the starch retains its granular form when in admixture with the film-forming substance and also when deposited on the textile. In this way the present invention avoids producing continuous films of starch which tend to stiflen the fabric initially, but which are broken up on washing.

The expression inert applied to the filler means inert with respect to the film-forming substance; to the dispersion medium and to the textile to be treated. The filler is preferably employed in a finely comminuted state, satisfactory results being obtained with a particle size textileby the deesterification of position before application of the second comporegard to the solubility characteristics of the film-forming substance and filler, and the nature of the textile to be treated. Further, the composition may contain a textile wetting agent, a protective colloid, a softening agent, a dyestuif; and the like, and other textile assistants.

' Various changes may be made in the process without transcending the scope of the invention. For example, the invention includes partial or complete coagulation of the first applied comsition, but in this case, the first composition is not completely dried before the second composition is applied. If desired, the textile may be impregnated throughout with the first applied composition which does not contain a substantial quantity of filler and the second composition which contains a substantial quantity of filler is applied only on one side of the impregnated textile.

By way of illustrating, but not by way of limiting the invention, there will be given the following examples:

Example 1.-A cotton bed ticking is treated on a padder with a composition comprising 4% alkali-soluble cellulose ether, 7% caustic soda and the remainder water. Without coagulating the cellulose ether or completely drying the treated material, it is back-filled while in a moist condition with a composition comprising 6% alkalisoluble cellulose ether, 9% caustic soda, 24% by weight of talc and the remainder water. The

back-filled fabric is then treated so as to coagulate the cellulose ether of both of the applied, compositions as by passing it into a bath containing a 10% aqueous solution of sodium bisulphite after which the fabric may be washed,

, softened, dried and otherwise processed in a below 200 mesh. It may be incorporated in the V composition in any suitable manner, as by dispersing it in a liquid preferably a portion of the solvent for the film-forming substance, and this liquid may advantageously contain a peptizing agent and a protective colloid to promote the formation of a uniform and stable dispersion. The quantity 'of the filler to be employed in the composition will depend, inter alia, upon the condition, nature and character of the filler and the nature and quantity of the film-forming substance. For example, when using starch as the filler, the starch may comprise from 25% to 100% by weight of the film-forming substance.

The film-forming substance is desirably dispersed in a suitable liquid which maybe a solvent therefor or a liquid which forms a colloidal dispersion therewith and the expression dispersion medium is intended to include solvents as well as dispersion media. The film-forming substance, filler and dispersion medium are mixed until asubstantially uniform composition is obtained. The dispersion medium is selected with known manner.

Ex mple 2.-A 64 x 64 cotton sheeting is backfilled with a composition comprising 4% alkalisoluble hydroxy alkyl cellulose, 7% caustic soda and the remainder water. The back-filled sheeting is partially dried'and then back-filled on that side of the sheeting first treated with a composition comprising 3% alkali-soluble hydroxy-alkyl cellulose, 2.66% caustic soda, 1.5% of Stien Hall Pearl starch and the remainder water. The starch is added to the composition in dry form with stirring. The back-filled fabric is then treated to coagulate the cellulose ether of both of the applied compositions, as by passing it into a bath containing 10% aqueous solution of sulphuric acid, after which the fabric is washed, softened, dried and otherwise processed in a known manner.

Of the various fillers herein disclosed, starch is characterized by having new and unusual advantages when employed in the process of the invention. The starch has the property of rendering the composition very stiff and of a consistency especially suitable for back-filling. Moreover, the addition of starch permits the use of smaller quantities of the film-forming substances in the composition. The textiles finished with starch filled compositions show a very high resistance to the loss of starch on washing in marked contrast to textiles which have been finished with a size consisting of starch alone.

It is to be understood-that by suitably varying the nature and amount of the compositions employed in the process of the invention, textiles having a wide variety of commercially valuable properties may be obtained. Among the novel effects obtainable is that the finished textiles are characterized by showing a superior anchorage of the filled composition to the textile. It is believed that this adherence is due to the fact that the second finishing composition containing the filler is applied to the textile while the first applied finishing composition is in a moist or gel state so that there is an actual fusion of thefilmforming substances of the two compositions. The products accordingly are stifier and more resistant to wear and abrasion than products heretofore produced.

In the specification the expression without complete drying is intended to indicate thatthe treated materials are not dried to the degree that commercial finished samples are dried, so that the invention contemplates that the impregnated material may be partially'dried, but ,not completely dried.

Having described my invention, what I claim as new and .desire to secure by Letters Patent is:

1. In a process for finishing an unfinished textile material with a coagulable cellulose ether and an'inert solid textile filler, the steps comprising firstapplying to said unfinished textile material a composition consisting of an aqueous" tile material witha coag'lflable cellulose ether and an inert solid textile filler, the steps comprising first applying to said unfinished textile material acomposition consisting of an aqueous dispersion of an alkali-soluble water-insoluble coagulable cellulose ether, said composition penetrating the textile, thereafter applying to the thus'treated textile, before completely drying said first-applied composition, an aqueous alkali dispersion of an alkali-soluble water-insoluble coagulable cellulose ether filled with a substantial quantity of colorless inert solid textile filler and thereafter coagulating the cellulose ether on the textile material; said applied compositions penetrating each other, whereby said first-applied cellulose ether composition serves to bind the filled cellulose ether composition to the textile thus producing a product substantially resistant to the loss of said filler during laundering.

3. In a process for finishing an unfinished textile material with a coagulable cellulose ether and an inert solid textile filler, the steps comprising first applying to said unfinished textile material a composition consisting of an aqueous dispersion of a coagulable cellulose ether, said composition penetrating the textile, thereafter backfilling; on one side the thus treated textile, before completely drying said first-applied com-' position, with an aqueous alkali dispersion of an alkali-soluble water-insoluble coagulable' cel lulose ether filled with a substantial quantityiof" inert solid textile fillerand thereafter coagulating the cellulose ether on the textile material,

said applied compositions penetrating each other,

stantially resistant to the loss of said filler during laundering.

2. In a process for finishing an unfinished texwhereby said first-applied cellulose ether composition serves to bind -the filled cellulose ether composition to the textile thus producing a product substantially resistant to the loss of said 1511- I er during laundering.

ROGER WALLACE. 

